/Engine/Source/Runtime/Engine/Classes/Engine/SkeletalMeshSocket.h
Utility that returns the current matrix for this socket with an offset. Returns false if socket was not valid (bone not found etc)
bool true if successful, false if not
bool GetSocketMatrixWithOffset ( FMatrix & OutMatrix, class [USkeletalMeshComponent](API\Runtime\Engine\Components\USkeletalMeshComponent) * SkelComp, const FVector & InOffset, const FRotator & InRotation ) const